The objective of this research is to develop new interferon inducing agents and to study mechanism of interferon induction. Based on the findings that polyribonucleotides are potent interferon inducing agents and that double strandedness is an absolute requirement, we propose to stabilize the double strand by formation of interstrand covalent bonds. The covalent bonds will be formed by alkylating the double stranded polyribonucleotide polymers with alkylating agents including novel phosphoraziridine compounds. The resulting covalently bonded double stranded polynucleotide polymer should not only be more stable to thermal denaturation but due to crosslinking with the alkylating agents, especially the phosphoraziridines, a "phosphorus cage" should shield the bases from enzymatic hydrolysis. The stabilized polynucleotides polymers will be tested for antiviral activity and interferon induction in tissue culture using Vesicular Stomatis Virus. Use of C14 labeled alkylating agents should provide a tool for studies involved in mechanisms of interferon induction. Since the label is not located in a normal cell constituent (nucleotide).